以Fe(CO)_(5)和含一个巯基的配体为原料,通过多步反应合成了两个新的[FeFe]氢化酶模拟物1和2;构建了以化合物1和2为光催化剂、藻红B钠盐(EBS^(2-))为光敏剂、三乙胺(TEA)为电子给体和质子源的三组分光催化产氢体系,该体系在pH值为12且...以Fe(CO)_(5)和含一个巯基的配体为原料,通过多步反应合成了两个新的[FeFe]氢化酶模拟物1和2;构建了以化合物1和2为光催化剂、藻红B钠盐(EBS^(2-))为光敏剂、三乙胺(TEA)为电子给体和质子源的三组分光催化产氢体系,该体系在pH值为12且体积比为1∶1的CH_(3)CN/H_(2)O溶液中,经可见光(λ>420 nm)照射4 h,最大产氢量为205.0μmol,相对于化合物2的催化转化数(TON)为51.4;研究表明,配体中含有较多的质子捕获位点,有利于形成产氢活性中间体H 2-2Fe2S(η2-H 2-Fe II Fe I)物种,从而提高催化剂的产氢活性,光生电子从1*EBS^(2-)化合物1和2的第一个电子的转移均为热力学可行过程,到化合物1和2的第二个电子转移是热力学不可行过程。展开更多
Photocatalytic reduction of CO2 to CO is a promising approach for storing solar energy in chemicals and mitigating the greenhouse effect of CO2.Our recent studies revealed that[(μ-bdt)Fe2(CO)6](1,bdt=benzene-1,2-dith...Photocatalytic reduction of CO2 to CO is a promising approach for storing solar energy in chemicals and mitigating the greenhouse effect of CO2.Our recent studies revealed that[(μ-bdt)Fe2(CO)6](1,bdt=benzene-1,2-dithiolato),a[FeFe]-hydrogenase model with a rigid and conjugate S-to-S bridge,was catalytically active for the selective photochemical reduction of CO2 to CO,while its analogous complex[(μ-edt)Fe2(CO)6](2,edt=ethane-1,2-dithiolato)was inactive.In this study,it was found that the turnover number of 1 for CO evolution reached 710 for the 1/[Ru(bpy)3]2+/BIH(BIH=1,3-dimethyl-2-phenyl-2,3-dihydro-1H-benzo[d]-imidazole)system under optimal conditions over 4.5 h of visible-light irradiation,with a turnover frequency of 7.12 min−1 in the first hour,a high selectivity of 97%for CO,and an internal quantum yield of 2.8%.Interestingly,the catalytic selectivity of 1 can be adjusted and even completely switched in a facile manner between the photochemical reductions of CO2 to CO and of protons to H2 simply by adding different amounts of triethanolamine to the catalytic system.The electron transfer in the photocatalytic system was studied by steady-state fluorescence and transient absorption spectroscopy,and a plausible mechanism for the photocatalytic reaction was proposed.展开更多
文摘以Fe(CO)_(5)和含一个巯基的配体为原料,通过多步反应合成了两个新的[FeFe]氢化酶模拟物1和2;构建了以化合物1和2为光催化剂、藻红B钠盐(EBS^(2-))为光敏剂、三乙胺(TEA)为电子给体和质子源的三组分光催化产氢体系,该体系在pH值为12且体积比为1∶1的CH_(3)CN/H_(2)O溶液中,经可见光(λ>420 nm)照射4 h,最大产氢量为205.0μmol,相对于化合物2的催化转化数(TON)为51.4;研究表明,配体中含有较多的质子捕获位点,有利于形成产氢活性中间体H 2-2Fe2S(η2-H 2-Fe II Fe I)物种,从而提高催化剂的产氢活性,光生电子从1*EBS^(2-)化合物1和2的第一个电子的转移均为热力学可行过程,到化合物1和2的第二个电子转移是热力学不可行过程。
文摘Photocatalytic reduction of CO2 to CO is a promising approach for storing solar energy in chemicals and mitigating the greenhouse effect of CO2.Our recent studies revealed that[(μ-bdt)Fe2(CO)6](1,bdt=benzene-1,2-dithiolato),a[FeFe]-hydrogenase model with a rigid and conjugate S-to-S bridge,was catalytically active for the selective photochemical reduction of CO2 to CO,while its analogous complex[(μ-edt)Fe2(CO)6](2,edt=ethane-1,2-dithiolato)was inactive.In this study,it was found that the turnover number of 1 for CO evolution reached 710 for the 1/[Ru(bpy)3]2+/BIH(BIH=1,3-dimethyl-2-phenyl-2,3-dihydro-1H-benzo[d]-imidazole)system under optimal conditions over 4.5 h of visible-light irradiation,with a turnover frequency of 7.12 min−1 in the first hour,a high selectivity of 97%for CO,and an internal quantum yield of 2.8%.Interestingly,the catalytic selectivity of 1 can be adjusted and even completely switched in a facile manner between the photochemical reductions of CO2 to CO and of protons to H2 simply by adding different amounts of triethanolamine to the catalytic system.The electron transfer in the photocatalytic system was studied by steady-state fluorescence and transient absorption spectroscopy,and a plausible mechanism for the photocatalytic reaction was proposed.
